Centrifugal separator



July 13, 1954 Filed Jan. 21, 1953 E. L. RANSEEN CENTRIFUGAL SEPARATOR 2 Sheets-Sheet l Inverfl'or': Erm b July 13, l954 E. l.. RANsEEN 2,683,562

CENTRIFUGAL SEPARATOR Filed Jan. 21, 1953 2 Sheets-Sheet `2 Patented July 13, 1954 UNITED STATES PTNT OFFICE 21 Claims. (Cl. 233-30) 1 This invention relates to improvements in centrifugal separators, and the like. The improvements herein disclosed are intended primarily for use in high G separators, that is, separators d in which very large centrifugal separating forces are developed; but it will appear that said improvements are not limited to use in such high G separators, and are of general application and usefulness. Separators embodying the present features of novelty may be used for producing separating actions for separating the components of fluid mixtures (either liquid or gaseous) in which the said components are very diflicult of separation. Included in such diflicult to separate mixtures are mixtures in which the specic gravities of the components are not greatly different from each other, as well as mixtures in which the components exert a mutual molecular attraction for each other which attraction must be overcome to bring about the separating action. Various kinds of diiiicult to separate mixtures, other than those specifically mentioned above may also be found to yield to the separating actions of separators embodying the herein disclosed features on invention.

The centrifugal separators herein disclosed are of a type and construction in which the main passage through which the materials travel during the separating process is long in comparison to the radial dimensional difference between the radii at which the heavy and the light components arefdelivered, so that the amount of radial travel which must occur during the separating process is relatively small. This radial travel may, in some embodiments of the present invention, be of the order of a thousandth of an inch, or even a few ten-thousandths of an inch. `The length of the main passage through which the material undergoing treatment travels during the separating action may, on the other hand, be of the order of an inch or in some cases, many inches. Accordingly, the distance of travel in the radial direction during separation is vastly smaller than the average length of travel along the main passage.

The main passage through which the materials move during the separating process is provided with a pervious partition through which the materials undergoing treatment move to either greater or smaller radial dimensional locations. This partition extends lengthwise throughout the length of the main passage or a considerable portion of such passage, and thus sub-divides said main passage into what I term sub-passages. These sub-passages are at dfferent distances measured from the rotative axis of the rotor. Due to the pervious nature of the partition the heavier component is enabled to move through such partition into the outer or larger distance sub-passage, the lighter component being correspondingly forced to move through the partition into the inner or smaller distance sub-passage. Interchange through such pervious partition may occur along the length of such main passage until finally a desired condition is produced at a location near the point of discharge where one or both of the separated components is or are delivered from the rotor. Generally there will be two discharge points in communication with the inner and the outer sub-passage, respectively, and suitable means will be provided to collect the discharged bodies of separated components.

In my co-pending application for Letters Patent of the United States, Serial No. 80,950, iiled March l1, 1949, and which became Letters Patent No. 2,626,747, dated January 27, 1953, I have disclosed a centrifugal separator embodying in general form the features thus far described as being characteristic of the disclosures of the present application, In that previous application the main passage is, specifically, shown as being spiral in form with its inner or inlet end formed at the inner or small diameter end of the spiral, and with its outer or delivery end formed at the outer or large diameter end of the spiral. Such spiral passage, when the structure embodies the same, encircles the rotor axis and is of progressively increasing radius from the inlet to the outlet end thereof. In the broader aspects of said invention, said passage circles the axis of rotation and maybe of more than 360 degrees encirclement or of 360 degrees of circlement or a less extent of circlement. In any case, however, the main passage is provided with the pervious partition through which the treated material may move during the travel of such material lengthwise of the said main passage; and in any case such main passage is divided by such pervious partition into sub-passages of different radii at any given location along the length of the main passage.

In that earlier disclosure I have shown various forms of such pervious partition, as well as various structural arrangements whereby the disclosed spiral form of such main passage may be retained notwithstanding the very large centrifugal forces which are developed during operation and for the production of high values of G. When it is desired to develop values of G of the order of several hundred thousand or even as much as one million or more, the rotative speeds are very large, and the centrifugal forces developed become enormous. These operations impose limitations which are dependent largely on strength of materials conditions in those materials which are acceptable for use in the handling of the materials to be treated; but is must be noted that a given value of G may be produced with less stress:l developed in the body of the rotor when'- the diameter ofthat rotor is reduced, accompanied by the needed increase of rotative speed to develop the Value of G which is desired. Accordingly it is desirable tovbe able to use as small a diameter of rotor as is consistent with the materials to be treated andi-the volume thereof to be treated per hour or other unit ofv time. It is found desirable, when building the rotor of comparatively small diametentoavoid.

the need of spiralling the main passage, and it is desirable to bring the separating treatment within a length of main passage which may be afforded by a single circlement of the rotor (or somewhat less than such single circlement), the mainpassage-being made truly circular inform measured from` the axis of rotor rotation, and beingk of uniformI radius throughout its length, measuredfromsuch axis of rotation. Nevertheless, itis very. desirable to obtain the benefits-of the pervious partitionwithin such main passage, so as to aid in retaining the already separated components in their separated condition, and to avoid re-mixing during further. travel along the mainpassage tothe delivery point.

Itis an object ofthe presentinvention to provide a separator construction in which the main passage comprises a. conduit extending around the rotative axis at uniform. radiusthroughcut the length of. suchpassage; and in which the perviouspartition within such main passage is of. av form. and construction admirablyv adapted to meet and withstand the enormous stresses to which. the structureA is subjected. in. operation. Stillto so. forinsuch. pervious partition that it willeffectively perform its intended functions of allowing the components. to movey through its body during the. separating. action,. and. atthe same time to. enable close and accurate manufacturing. operations in. the production of. the foraminations. with which. such partition is provided. 'Ehese foraminations may be of theorder of thousandths or eventen-thousandths of an inch dimensioninatleast onedirection of their openingsso, that very close. tolerances.` must be adheredvto during themanufacturing.operations byk which said partitions .areproduced Under the great centrifugaLforcesv being developed by the separator, foraminations of thesesmall sizes will pass amply sucient materialV volume. to meet practical needs.

More specifically, it is a further object of the invention, to provide the rotor with inner and outer cylindrical bodies which are so. formed that a circular annular space is left` between them when they are set into telescoping relation with respect to. each other; and the proximate. surfaces of these two bodies are provided with circling grooves or semi-passages which are in direct registry with the inner and outer faces of the pervious partition. Those grooves whichare formed on the inner cylindrical body are connected together and to an inlet conduit, and those grooves which are formed on theY outer cylindrical body are connected together' tc an outlet conduit or. conduits. Thus the material undergoing treatment is subjected to a pressure differential at the opposite faces of the pervious partition, and that pressure differential causes movement of the separating material through such partition. Suitable delivery conduits are also provided in communication with the grooves which come into registry with the inner face of the pervious partition for delivery of the lighter component material.

Specifically, a' preferred. embodiment. of my present invention` is onel in whichthel pervious partition comprises a thin sheet of metal, of the order of, say, one thousandth inch in thickness, and whichV sheet is slit at numerous locations over its area, such slittings being produced without removal of any substantial portion of the materialof the sheet. These slits are conveniently located' in alignment with each other lengthwiseofs the rotor, but the slits of each such line are not connected together but are separated by uncut sheetmaterial, so as not vto sever the sheet bodily across the sheet, or lengthwise of the rotor. Also, thefslits of successive. lines preferably break joints so that when the desired area of the sheet hasv thus been slitted it will be provided with numerouslinesof slits, and with the slits of the successive lines breaking joints. After. the slitting operation the sheet may. be subjected` to a rolling or other sur-facingtreatment so as to. substantially.- close the slitsvand restore asubstautially smooth surface. to eachface of the slitted sheet.

Such a slitted sheetisnot impervious to movement of the material throughl its slits under the conditions existing in such-separatorsas are herein contemplated. These slitswill actually have slot openings of minute size along, the lengths of the slits, andunder the pressure conditions existing in the separator the material components will move readily through suchI minute openings during the separating actions. In case, however, it shouldbe desired: to produce enlargements-of these slitssuchresult may readily be produced by slightly stretching,` the slitted sheets so as to draw the slits apart with corresponding deformation=of the uncut materialandperma-nent stretch of the entire sheet lengthwise. Such a. slightly stretched sheet would resemble what is well known in the-arts as` expanded metal, but the amount ofthe xpansion would be very small. Generally, however, it will be found unnecessary tov thus enlarge the slits.

The pervious partition above referred to is seated betweenthe inner and. outer cylindrical bodies already referred to-and` occupies the circular annular space which is, left between said bodies. In suchcase the thickness of the sheet from` whichY the pervious partitionY is madey issubstantially equal. to the radial dimension of suchfannular space so as to fullyv occupy it. With thisarrangementthe entireinner. and outer surfaces of the pervious partition sheet are in contactlv with the proximate surfaces of the innerandouter cylindrical bodies, with. the exception of the grooved portions of said bodies, already. referred to. Preferably the slitting of' the sheet-is so done that the slits come intoregistry with such grooves ofil the cylindrical bodies; but even4 when. such registry does not-exactly occur the separating components will find their way throughminuteopenings or spaces between the surfacescf. thesheet andthe cylindrical' surfaces of the two bodies. In order. for the components to move between the groovesof one cylindrical body and the other. cylindricalbody, however, it

5 will be necessary for such components to move through the slits of the sheet.

The two components which are separated find their Way to the opposite faces of the partition above referred to; the heavier component moving to the outer or larger diameter face of the partition, and the lighter component moving to the inner or smaller diameter face of said partition. The delivery passages connect to spaces in communication with such outer and inner partition faces for delivery of the respective components to suitable conduits for iinal delivery from the separator. In many cases the desired completeness of separation Will be produced by use of a simple form of separator embodying the features thus far discussed. In cases in which, due to the nature of the mixture being treated, or to molecular attractions existing Within the mixture, provision may he made for repeated or multiple separation operations by use of structures embodying the features of invention herein disclosed. I have made provision for such multiple treatment of the materials and have disclosed herein various means to secure such treatments.

Such multiple treatment may be effected in several ways. One way of effecting such multiple treatments comprises rst effecting a rough separation of the heavier and lighter components, to produce heavy and light component bodies of the material, but either of such bodies may include a small percentage of the component other than that intended to be included in such body. Thus, the heavy component may include a small proportion of lighter component, or vice versa. I

Generally, however, it will be desired that one or the other of the components shall be of a specied purity, including not over a specified small percentage of the other component. Included in the forms of separator herein disclosed are embodiments for producing the desired purity of product for either the heavier or the lighter component. When the desired purity of component is to be secured in the heavier component, I have made provision for first subjecting the mixture to a primary separation operation to produce the roughly separated components. I have then made further provision in the separator for subjecting the heavier component thus produced to a further separating operation for removal of substantially all remaining portions of lighter component. On the other hand, when the desired purity of component is to be secured in the lighter component, I have made provision for rst subecting the mixture to a primary separation operation to produce the roughly separated components. I have then made further provision in the separator for subjecting the lighter component thus produced to a further separating operation for the removal of substantially all remaining portions of heavier component.

In the hereinafter disclosed means for effecting the multiple separating operations just above referred to, I have provided the secondary of refining separating means of greater diameter than that means which is used during the primary or rough separating operation, so that higher values of G are developed during the secondary separating operation, and thus such secondary separation operation is carried on under more advantageous conditions for effecting substantially complete removal of the non-elected component from the elected component.

As another embodiment of my present invention I have also hereinafter disclosed structures in which successive portions of one of the components may be individually delivered and collected, so that the purity of the other component will be successively increased to a final degree of purity which is desired in the delivered body of such component. I have disclosed means embodying the above stated features, for removal and delivery of successive portions of the lighter component, so that the purity of the heavier component is progressively increased; and conversely, I have also disclosed means embodying said above stated features, for removal and delivery of successive portions of the heavier component, so that the purity of the lighter component is progressively increased.

As a further modification of embodiments of my present invention, I have also disclosed a form of structure in which two or more of the slitted partitions are located in tandem or multiple series arrangement between the cylindrical bodies of the rotor previously referred to, so that the separating material must move through both of such slitted partitions during the separating operation. I have also disclosed an embodiment in which there is provided a form of ne mat in contact with one or more of the partition faces so that the material moving to or from the slits of such partition must also move through such mat during the separating process. When two or more of the slitted partitions are provided as already mentioned, such a mat may be included between the proximate partition surfaces so that the separating material must move through such mat in passing between such partitions.

I contemplate various forms and kinds of such fine mats as being Within the purview of my present invention, when used. Thus any suitable semi-permeable form of membrane may be used, Such as unglazed porcelain ground into a fine powder and then compressed under heavy pressure into a self-sustaining sheet. Such a sheet will in reality include an enormous number of very minute passages or openings in itsbody, communicating with each other, and providing a membrane through which the separating material may move under such pressures as exist in separators developing high values of G. Or, as a modification, such ground porcelain or like material may be sprayed onto the surface of the slitted partition under slightly moistened condition. It will be found that when dry such a sprayed surfacing will adhere to the partition surface tenaciously enough to ensure production of the desired matting effect in contact with the partition surface to produce the desired effect of improving the separation operation otherwise produced by the separator without such mat included in the structure.

When such a mat as hereinbefore referred to is included in the structure it will be found that, by using a mat of very fine texture or structure, elemental portions of the mat will work themselves into the slitted openings of the partition thus further improving the control of the separating operation.

Other objects and uses of the present invention will appear from a detailed ydescription of the same, which consists in the features of construction, and combination of parts hereinafter described and claimed.

In the drawings:

Figure l shows in perspective a rotor embodying the features of my present invention, por- 4tions of; the rotor elementsbeing brokenaaway :to .reveal the interiorconstruction; and the .embodi- `inentfshowri inathis-iigureis one .in which the rotor `includes inner and .outer cylindrical bodies "which are so formed as to provide'the desired -thinannular space lbetween the proximate sur- .faces of such bodies, 4.such proximate surfaces 'being provided with grooves yextending partially 4around the bodies, and with cross'grooves providing for transfer of materials between such grooves or into or fromsuch grooves as needed;

`and thestructure=shown in this gure includes a :single slitted partition set into such annular .space 4so as to control-and assist the-separating operations;

Figure 2 shows'a ifragmentary portion of the structure shown in `Figure l, but developed into aplanar body instead or acylindrical structure;

and this igurezshows the parts in perspective,

flow of 4theseparated component for collection inyasuitable stationary collectingunit, such, 'for example, as shown in Figures 2 to I of myaioresaid earlier application and patent;

Figure 3 shows, Imore orless schematically, a

modified embodiment of separator embodying the Afeatures of :my present invention, `in which embodiment provision is made :for successively removing portions of lightercomponent for progressive reinement'of the non-removed heavier f component;

Figure 4 shows'more or less schematically, an-

other modified embodiment of separator embodying the features-of my present invention, in'which embodiment provision is made for successively removing portions of heaviercomponent for progressive refinement of the non-removed lighter component;

Figure-5 shows, more or less schematically, an-

other :modified lembodiment of separator `embodying the features of my presentinvention, in which'embodimentprovision is made'for stage l. 'renement'of one of the components, and in `this figure such stage refinement comprises removal of lfurther portions of the lighter component from previously separated heavier component, thefurther Aremoval being eiiected under conditions of structure such asproduce an increased value of G during such further removal;

Figure 6 shows, more or less schematically, an-

other modified embodiment of separator embodying the features of my presentfinvention, in

lwhich embodiment provision is made for stage refinement of one of the components, and in this .ligure such stage renement comprises removal of further portions of the heavier component from previously separated lighter component, the further removal being effected under conditions of structure such as produce an increased value of G during such further removal;

Figure '7 shows a view similar to that of Figure 2, but showing a further modified form of structure in which two slitted sheets are provided through which the separating materials must move in tandem; and in this modication ,I have also included a sheet or mat of fine tex- .ture and considerablefthinness such as previously 8 `referred to herein, `located between the two slitted sheets; and

:Figure -shows, more or less schematically, a fragmentary segmentof a rotor of two stage type, such as shown in Figures 5 and 6, but in which rotor there-areprovided two of the slitted -sheets in each "stagef and with a fine mat located Abetween the slitted sheets of eachrstage.

Referring to the drawings, andto Figure 1 in particular, the rotor'therein illustrated includes the inner'cylindrical body 'I0 shown as comprising a tubular element, an outer cylindrical body II shown Yas also vcomprising-.a tubular element, and end rplate elements I2 and I3. The end :portions of the'body IEI are preferably shouldered as'shown at I4 and I5, andthe diameters'of the end plates are made-such as to permit the peripheral portions -of said vplates to seat snugly againstthe correspondingshoulders vI4 and I5. The length of the Ainner cylindrical body IB is made such that the'end plates come into snug ,engagement vwith -the ends of such body I9 at 'thefsametime said shoulders are engaged bythe fend plates. The shaft 'I6 extends centrally through both of the end plates and through the inner body AI0; andthe end plates are conveniiently threadedonto this shaftor are-drawn into .tightengageinent withthebodies I9 and II by nuts-'such as I'I.

The vshaft isprOVided-Withthe inlet or mixture supplypassage I8 into which the untreated mixture is fed yin suitable-manner (not shown), and withinthe body I0 suitablei'adial openings such fas I8 -are provided in communication with this passage I8 for delivery of the untreated mixture vintofthe hollow interior of the-body I0. At-this .pointvit may be noted-thatthe 'innerbody rIi] as :illustrated issplit lengthwise, and a veryslightly tapered Awedge section, 20, of the same radial =dimension^as thethicknessof the body `I() is-set into the split portion of such body I0 'during the .assembly of lthe structure. This very slightly wedge -form'section is of Aarcuate embracement of .amount `to `slightly yexpand the inner `cylin- .drical body I0 during-assembly, and-at-the same time to ,complete the encirclement of such body -Iil into acompletefcylinder asshown. The-pur- Ypose of `this structural feature will appear presently.

The. outer. surface of the inner cylindrical body .I0 is provided with oneor more circling grooves 2| `.which Ado not completely encircle such body, `but 'leave an .ungroovied .section 22 .between the groove .ends and extending across the body I0. A radially extending opening 23 connects 4the material supply end Yof each ,of the grooves 2I with the interior of the .inner body I0 so that, once such interior of the body I0 has become iilled with untreated mixture, such mixture may Ythereafter move through the .openings A23 into the several grooves 2I as required to .ensure a continuous treatment operation. These openings 23 as shown in Figures 1 and 3, 4, 5 .and 6. Preferably one or more lengthwise extending grooves 24 are provided at or near to the ends of the grooves 2I remote from the inlet openings 23, so as to connect together all of the said ,grooves as shown in Figure 1. These grooves 2d serve Ato collect the separated component from the grooves 2| .and deliver such component endwise of .therotor for discharge from therotor, or foinfurther fstage.treatment, as desired.

The innersurface of the cylindrical body I I is also provided with circling grooves 25 which do not Acompletely encircle said inner surface, 4but 9 leave an ungrooved section 26 (see Figure 1) extending across the rinner surface of the body II. In Figure 1 a portion of such ungrooved section 26 is broken away, but a portion of such ungrooved section appears in said Figure l. Preferably the grooves 25 of the cylindrical body II and the grooves 2I of the cylindrical body I0 lie more or less in radial alignment with each other, and the ends of said sets of grooves may also align more or less radially with each other. Accordingly it happens that the delivery ends of the grooves 25 lie Within the portion of the cylindrical body which is cut away in Figure 1. Thus said delivery ends of the grooves 25 lie preferably above the ungrooved portion 22 of the cylindrical body I 0. In Figure 2 I have shown a fragment of a portion of the cylindrical bodies IIJ and II, but in nat or developed form, and in that gure I have shown a delivery opening 2l extending radially through the outer cylindrical body II and in position to receive and deliver heavy separated component to the exterior of the rotor. Instead of and preferably in substitution for such delivery opening or openings 2l there may be provided one or more lengthwise extending grooves 25 (see Figures 3, 4, 5 and 6) on the inner surface of the cylindrical body I I and connecting the end portions of the grooves 25 together and also connecting with an outlet or delivery opening in one or both of the end plates I2 and I3. Also, one of the end plates I2 or I3 is provided with an axially extending delivery opening (cut away in Figure 1) which delivery opening registers with one of the lengthwise extending grooves 2li near the delivery ends of the grooves 2I for :r

delivery of light component material to the exterior of the rotor. The relationship of the various grooves 2I, 25, 24 and 28 to each other and to the inlet or supply openings 23, and the delivery openings, are shown in Figures 3, 4, 5 and 6 for various embodiments of my present invention.

It now appears that I have made provision for delivery of lighter component material from the grooves ZI, and for separate delivery of heavier component material from the grooves 25, delivery of both such components being from the rotor through suitable openings. I have not herein illustrated means to separately collect the delivered components of materials, since various embodiments of such means suitable to the particular operations being carried on may be used. However, in the aforesaid earlier application, Serial No. 80,950, to lbecome Letters Patent No. 2,626,747, issued January 27, 1953, I have disclosed various means to separately collect the separated components and deliver them from the rotor in such separated condition; and various of such earlier disclosed collecting means are usable in connection with rotors embodying the features of novelty disclosed in this case. Other collecting means may also be used for similar purposes.

The exterior diameter of the inner cylindrical body IU is slightly less than the interior diameter of the outer cylindrical body II, so that when said cylindrical bodies are telescoped together there is provided a slight or thin annular clearance between said bodies. This clearance may be of the order of a few thousandths of an inch or even considerably less amount, the amount of such clearance depending on the design of the rotor structure, the materials to be treated by it, the cylindrical sizes of the bodies, and other factors of design. However, by reason of the fact that both of such cylindrical bodies are of truly cylindrical circular form it is possible to establish the sizes of the proximate inner and outer surfaces to very close manufacturing tolerances by grinding and like nishing operations. I shall presently refer to the provision of the Wedge shaped section 2li of the inner cylindrical body, but at this point it may be stated that during the finishing operations just above referred to, such as grinding, etc., the exterior size of the finished body I5 may be made slightly undersize as compared to its finally desired size, so that upon inserting such wedge element 20 into place such inner body Iii will be slightly expanded to its desired final size.

The slitted partition is accommodated within the thin annular clearance above referred to. This partition is designated 29 in various of the figures. It comprises a thin sheet of material, preferably metal oi high tensile strength and of composition to resist rhemical actions by the materials to be treated. This sheet is of width to substantially fill the length between the inner faces of the end plates I2 and I 3, as shown in Figure 1. When this sheet comprises a continuous circular element it may be formed from a section or length of thin tubing, or it may comprise a length of strip wrapped or brought into circular form and with its proximate ends substantially in contact with each other, or even welded or brazed together, or integrated in other suitable manner. When formed from a sheet as just explained the line of joinder is preferably located opposite to the non-grooved portion 22 already described.

This sheet is die slitted to produce the lengthwise extending slits 3U, best shown in Figure 1, but also shown in various other figures, and by the term lengthwise I here contemplate lengthwise of the rotor axis, that is, across the length of the partition strip measured around the circle.

Preferably these slits are very numerous, and preferably also they are formed in successive groups, each group including a number of the slits located in alignment with each other but the slits of each group being discontinuous from each other so that the metal of the partition strip is not severed completely across its width, being the length of the eiective portion of the rotor. K Preferably, also the slits of the successive groups break joints, as well shown in Figure 1, and in Figure 7, presently to be described. Thus the partition is in effect provided with a great number of very narrow slits staggered over its entire eifective area. However, it is noted from Figure 1 in particular, as well as Figures 3, 4, 5 and 6, presently to be described, that slits are not needed in those portions of the partition sheet which do not register with grooves 2I or 25, and accordingly no slits are shown in that portion of the sheet which registers with the non-grooved section 22 of Figure l.

These slits are readily produced by conventional shop operations by die cutting with very narrow blades or cutting edges. Due to the thin dimension of the sheet such cutting operations are readily performed without serious distortion of the sheet surface. However, after cutting the slits it may be found desirable to roll the sheet between smooth rollers in order to iron out any slight distortions which may have been produced, especially at the slit edges. Also, after the slits have been produced, and especially after such further treatments as the ironing operation just referred to, it will be found that to the unaided eye the slits will appear to be completely closed.

However, careful and close examination of the so treated sheet will show that actually each slit includes numerous minute irregularities in its edges, so that even when the ironing operation has been performed there will still remain enormous numbers of very minute openings through the sheet, and through which the materials undergoing treatment may and will move. The iineness of these minute openings will greatly assist in producing separating operations between components which are diiiicult of separation, and/or which are of specic gravities which do not differ greatly from each other.

The so-slitted partition is inserted into place between the exterior surface of the inner cylindrical body IU and the interior surface of the outer cylindrical body Il. The parts are so proportioned that the annular clearance between said surfaces is substantially filled by such partition sheet. Due to the thinness of the sheet, and consequently its small degree of stiffness, as well as its diameter in comparison to its thickness, and. due also to the thinness of the annular clearance into which the sheet is to be inserted, as well as other practical conditions, special means shouldV be provided to enable nal assembly of the inner and outer cylindrical bodies with the partition sheet in place, and without crinking or otherwise deforming the partition sheet. Such provisions must be made in order that exact registry of the parts shall nally be secured, and to ensure good andeffective running of the rotor and production of the desired separation operations. Conveniently the partition sheet may be made of size slightly less than the internal size of the outer cylindrical body so that the partition can be run endw-ise into place in such body. However, such slight undersize of said partition sheet will mean that it cannot be set over the outer surface of the inner cylindrical body Ill, unless said body be slightly contracted in size during the assembly operations. Accordingly, I prefer to form such inner body Il! of slightly under size, andsevered lengthwise toiaccommodate the wedge shaped element 2Q, already referred to. By this means said inner body Ill without the wedge element in place will be naturally biased to its smaller size, so that the tubular partition sheet may be readily set onto such inner cylindrical body, even with a slight clearance around such body. Then these parts, including the inner cylindrical body and the partition sheet thereon, may be run into the outer cylindrical body with ease. Then, and with the parts properly registered with respect to each other angularly, the wedge element 26 may be carefully moved-endwise (parallel to the rotative axis) into place, thus effecting the slight expansion of the inner cylindrical element needed to produce the desired results. |These results include that slight expansion of the inner cylindrical element or body necessary to bring its-outer surface into complete engagement with the inner surface of the partition sheet; then a further expansion of boththe inner cylindrical body and the partition sheet or tube, so astobring the outer surface of such partition sheet or tube intoproper engagement with the inner surface of the outer-cylindrical body. Having effected these operations it will be evident that the partition sheet or tube will be firmly locked between the two cylindrical bodies, and-with substantially continuous surface engagement of the inner andouter partition surfaces with the proximate cylindrical surfaces of the cylindrical bodies (with the exception,Y of course, of the grooves whichY have been formed in saidbodies as already described);

Now during the foregoing slight expansion of.

the partition sheetv or tube, it' is evidentf that a slight stretch thereof musti occur. Such stretch may be readily produced without any dangerV of fracture or" the partition material, since the'slits may be very. slightlyA opened during such operation,` producing inV effect a very slightly expanded formof sheet metal element. However, by proper design ofthe-parts andproper proportioning thereof, suchexpansion opening of the slits may be held withina value which is acceptable accordings to 4thematerialsto be treated, and for other considerations. It is here to be remembered thatV separators embodying the featuresoffthe presentinvention are-usable for separation operationslwhich may be classed as "approaching molecularA separations, and that the slits may be of widths of the order of ten-thou.- sandths or even hundred-thousandths of an inch dimensions. In some cases it may be found desirable to use partition sheets of thickness of the order of less than oneone-thousandth of an inch or even much thinner. Partition sheets or tubular elements of such thinnesses may be read.- ily assembled into the'y rotor unit by use of the operations and constructions already disclosed herein.

The embodiment shown.V in Figure 1 maybe considered as a simple'formof separator or centrifuge embodying the present invention. In.

this case there isbut aasingle separating operation, and-the two separatedcomponents are separately delivered'` withv but.. a single completeseparation operation. In Figure I have shown a modified arrangement, schematically shown, in which the inner-andA outer cylindrical bodies are provided with companion sets of grooves according to the principles already explained.; butin the present case I have subdivided the complete circle into four sub-sections, 3l", 32, 33 and 34, each subtending a selected arc. In the showing of Figure 3 all of these sub-sections are of` equal arcuateembracements, namely,.90 degrees. The grooves of the .outer` surfaceof the inner-cylindrical body and'of the innerl surface-.of the outer cylindrical body,. are limitedin arcuate embracement to correspond to the-subsections; butin the showing of Figure 3 the desired results to be described are secured bycarrying the grooves of the inner surface of` the outer cylindrical body through the complete arcuate embracement of all four sub-sections, with provision for only a single ungroovedseotion, such asthe ungrooved section Zlof Figure 1'.. Thus; the grooves 25el on the inner surface of the outer cylindrical body correspond to the grooves 25.-of` Figure 1. However, the grooves 2l of Figure l' have now been replaced by thefour sets of grooves 21a', 2W', 2W" and 2l". The inlet passage or passages 23a lead only to the inlet ends of the'grooves 2 In. The delivery end'sofi said'. grooves 21e connect with a lengthwise or axially extending delivery groove or grooves 24a by which lighter component separated in the sectionV 3i is removed from the rotor; andin this .section 3l the heavier come There will be some portion Thus a` further re- 13 within the section 32; and the delivery groove or grooves 24a" are provided in connection with the delivery ends of such grooves Zia for removal of a further fraction of lighter component. Then the thus primarily refined heavier component will pass to the section 33 where a further refining operation will occur, further portions of previously unseparated lighter component iinding their way inwardly through the slitted partition and to the groove or grooves 2W". The delivery groove or grooves 242W are provided at the delivery ends of the grooves 2 ia" for removal of a further fraction of lighter component. Finally, the thus secondarily refined heavier component will move into the section 34 where a further refining operation will occur, further portions of previously unseparated lighter component finding their way inwardly through the slitted partition and to the groove or grooves ZIM". The delivery groove or grooves 24am' are provided at the delivery ends of the grooves 2 Iam for removal of a further fraction of lighter component.

It is now apparent that in the arrangement of Figure 3 I have provided an arrangement, embodying the features of my present invention, and in which the heavier component maybe successively refined by successive removals of fractions of previously unseparated lighter component, so that the heavier component is nally delivered in that degree of reiinement which may be desired or specified. It is also evident that with this arrangement the several fractions of lighter component which are successively removed by the successive refining operations are individually removed from the rotor, and may thus be individually delivered into separate receivers.

The arrangement of Figure 4 is similar to that of Figure 3, in principle, but in the present case of Figure 4 the lighter component is the component which is treated to successive refining operations and with individual deliveries of the successively removed fractions of previously unseparated heavier component. In this case the grooves 2lb correspond to the grooves 2l of Figure l and are carried around from the inlet opening or openings 23h. The groove or grooves of the inner surface of the outer cylindrical body are, however, subdivided into the grooves of 25h', 25V', 25V, and 25b; and the delivery groove or grooves 2gb are provided for these subdivided grooves 25h, said delivery grooves being designated as 28h', 2th, 28W and 28b for the subdivided sets of grooves, respectively. In the light of the detailed description already given respecting the arrangement of Figure 3 it is believed that the arrangement of Figure 4 will be readily understood, it being understood that the lighter component is thus successively subjected to the progressive rening operations, and that the removed fractions of previously unseparated heavier component are individually delivered from the rotor, and may be individually received and collected.

It is here noted that in the arrangements of Figures 3 and 4 all of the separating sections are of the same diameter, and therefore all produce the same value of G during the various rening operations. In Figures 5 and 6 I have shown another set of arrangements in which the separating sections are of progressively increasing diameters, so that the values of G in the successive sections progressively increase.

In the arrangement of Figure 5 the raw material moving through the inlet or inlets 23 is first subjected to treatment in the section 35 of smaller diameter, the lighter component moving to the groove or grooves 2|c and the heavier component moving to the groove or grooves 25'. The delivery groove or grooves 211 are provided for delivery of the separated lighter component as a separate body. Around the section just referred to is another section, 3e, of larger diameter, and including the groove or grooves 2 le for lighter component and the groove or grooves 25" for heavier component. The radial passage 31 communicates from the delivery end of the groove or grooves 25C' of the first or smaller diameter section 35, to the inlet end of the second or larger diameter section 35, it being noted that thereby the heavier component from the section 35 is brought to the section 36 for further treatment, the lighter component separated in the section 35 having been delivered from the rotor through the groove or grooves 24. The delivery ends of the sets of grooves 21C and 25 of the section 36 deliver the separated components produced in such section 36 to the delivery groove or grooves 24C and 28C, respectively. Thus this arrangement of Figure 5 serves to produce a secondary separation operation on the heavier component rst produced, and under a value of G which is greater than that used in the rst separation operation.

The arrangement of Figure 6 is similar to that of Figure 5, with the exception that in the case of Figure 6 the secondary separation treatment is produced on the previously separated lighter component. In this case the primary separation treatment occurs in the section 38 and the secondary separation treatment occurs in the section 39. The radial passage 40 is provided for transfer of lighter component from the section 38 to the section 39 where such lighter component is subjected to a further secondary separation operation. In view of the detailed description of Figure 5 it is believed unnecessary to recite a detailed description of the structure and operation of the showing of Figure 6, as it is believed that the same will be readily understood. It is noted, however, that in the case of Figure 6 the secondary separation operation, performed on the previously separated lighter component, is carried forward under a higher value of G than is used in the iirst or primary separation operation.

If desired more than one of the slitted sheets may be provided within the main passage through which the material which is undergoing treatment flows. Thus, in Figure 7 I have shown in fragmentary form, a portion of the rotor, but in flat developed form, and in which two of the slitted sheets are included between the inner and outer cylindrical rotor bodies. These are the two sheets di and 42, and as shown in Figure 7 each of them is provided with the slits 3Q. If desired both of these sheets may be set directly into facial contact with each other and between the cylindrical rotor bodies; but in the showing of Figure 7 I have included a thin iine mat or the like, 43, between the slitted sheets. This mat may be of any suitable material and texture or physical arrangement and structure, such as I have previously mentioned herein. Or it may be of such brous materials as nylon, Daeron, glass wool, or any one or more of numerous materials of a fibrous nature; but preferably, in view of the nature of the separation o-peration being carried on, such mat should be of very fine physical structure.

It is also noted that when such a supplemental rmat is included in the main passage, together aces-,5621:

with the Vslitted sheet or sheets, minute portions ofthe mat, such as Aminute portions of matbers,

will find their way intothe slits of the'sheets,Y

ofthe figures the radial dimensions of the slitted sheets, and of the mat, when used, and of the grooves, etc., areegreatly exaggerated, andthat generallyv these dimensions will be of the order of; hundredths or even thousandths of an inch or less, and that such showings in exaggerated-size have been made forv purposes of ease inillustration. as well as clarity of description and disclosure.

In'the specific structures `herein illustrated: and described I have shown a pervious partition in the form of a thin sheety which is provided.

with foraminations in the form` of the slits extending through said sheet'. I have also referred to. forms of mats which may. sometimes be used within the passage wherein the separating actionis proceeding in order to assist inholding the separated components or separated bodies .in the separated. condition. Both such partition and such mat. or mats shall be of form and.

structure to allow the necessary movement or transfer. of the separating materials or components through. them. I have mentionedv a partition comprising la slitted sheet, and. I have; mentioned certain forms or compositions of. mats and structures thereof. In so doing. however, I wish it understood that I do not intend to limit myself to such forms or Acompositions of said parts, except as I may do so in the claims f to follow.

The partition itself may compriseza form of mat material of pervious nature so that the materials and components being treated can move; through the body of such pervious "partition Without need of providing slits or other special openings through such. partition Gr. again, suitable` ma material or partition material may be provided within the annular space and/or within the grooves,v or both, such material being. sufficiently perviousto allow the necessary; movement of the materials and con ponents being treated, through the body of such partition or such mat fclaim: 1. In a; centrifuge a cylindrical rotor, means to journal said rotor for rotation about an axis` co-axial-with-.the roter cylinder, rotorl being formed to provide an annular cylindrical main passage within the body of the rotor, a sheetlike partition Within said main passage and extending substantially the fullaxial dimension of said. passage and substantially the full'- annular dimension of said passage to sub-dividesaid pas sage into inner and cuter sub-passages of different radii measured frointhe axis of cylinder rotation, aY fiuid supply conduit in connection` with the main passage for supply of fluidt'o the main passage` adi acent to one vendof saidpassage, andindividualfiuid delivery connections from the sub-passages, said partitionfbeing provided wi h numerous fiuid conducting openings through its body to establish fiuid transfer openings between the sub-passages.

2. A structure as defined in claim 1, wherein said partition comprises a thin sheet provided with numerous slits through the thickness of the sheet and distributed over the area of the sheet.

3. A structure as defined in claim 2 wherein said slits are discontinuous from each other and wherein the slits are relatively positioned in the sheet in such locations as to break joints with each other.

4. A structure as defined in claim 2, together with a foraminous mat of fine texture in facial contact with at least one face of the partition sheet and overlying the slits of said sheet.

5. A structure as defined in claim 4, wherein said foraminous mat comprises a sheet like body of finely ground material which is substantially chemically inert to the materials being treated in the centrifuge, and the particles of which finely ground material are adhered together into a'substantially continuous porous body.

6. A structure as defined in claim 4, wherein said foraminous mat comprises a fibrous structure composed of fine fibres in matted form.

'1. A structure as defined in claim 1 wherein the annular cylindrical main passage is provided with inner and outer cylindrical walls and wherein said inner and outer cylindrical walls are provided with circling grooves to establish the inner and outer sub-passages.

8. A structure as defined in claim '7 wherein the said inner and outer cylindrical walls are in surface contact with the sheet like partition at locations between the circling grooves of said walls to thereby support said partition in such surface contacting locations.

9. A structure as defined in claim 1 wherein the cylindrical main passage is co-axial with the axis of rotation and is of substantially the saine radius of rotation about said axis at all points around the annular dimension of said main passage.

10. A structure as defined in claim '7 wherein the cylindrical main passage is co-axial with the axis of rotation and of substantially the same radiusof rotation about said axis at all points around the annular dimension of said main passage, andl wherein said circling grooves are discontimiousY around said axis of rotation.

11. A structure as defined in claim 10 wherein the discontinuity of the circling grooves is locatedV in an arcuate section adjacent to the end of the main passage which is in connection with the uid supply conduit.

12. In a centrifuge a cylindrical rotor of substantially uniform diameter throughout its length, radially extending end walls at the ends of said. rotor, means to journal said rotor for rotation on its cylindrical axis, means within the body of saidrotor providing a circling main passage within the body of the rotor circling said rotor and extending between said end walls, said means Within the body of said rotor providing impervious inner and outer enclosing surfaces of said. circling main passage, an inlet connection to said main passage at one end thereof, and communicating withsaid passage at a location of smallradius measured from theaxis, of cylinder rotation, outlet connections from said passage: adiacenti to the other: end'there'of, at least one of.' said outlet connections communicating 17 with said passage at a location of radius, measured from the axis oi cylinder rotation, greater than the radius of the inlet connection aforesaid, together with foraminated means within said main passage and extending along the main passage in circling direction within the rotor to subdivide said main passage into larger and smaller radius subpassages located within the main passage and extending along the main passage in its circling direction and both embraced between said impervious inner and outer enclosing surfaces, said foraminated means being provided with numerous radially extending openings distributed along said foraminated means lengthwise of the main passage and establishing communication through said foraminated means between the larger and the smaller radius sub passages at various points along the circling path oi the main passage to permit interchange oi materials through said openings of the oramiu nated means under centrifugal action at various points along the circling length of the main passage, the main passage being co-axial with the axis of rotation and of substantially the same radius of rotation about said axis at all points around the circling length of said main passage.

13. A structure as dened in claim 12, wherein said ioraminated means comprises a sheet of suitable material provided with numerous small fluid transmitting openings through its thickness establishing communication through said sheet be en the sub-passages.

. in a centrifuge a cylindrical rotor comprising cfr-axial inner and outer cylindrical bodies, the cuter cylindrical body being of tubular form and provided with a cylindrical opening of size to accommodate the inner cylindrical body in telesccping fashion leaving a thin annular clearance between the inner surface of the outer cylindrical body and the outer surface of the inner cylindrical body, a foraminated sheet within said annular clearance and subdividing said annular clearance into an inner sub-passage and an outer sub-passage, and means to journal said parts for rotation about an axis co-axial with the cylincrical bodies, said parts being formed to provide inlet conduit for inlet supp'ly of untreated material into the annular clearance between the cylindrical bodies, and also being provided with separate delivery conduits for separated components, there being one delivery conduit in communication with each of the subpassages.

15. A structure as dened in claim 14, wherein the outer surface ci the inner cylindrical body is provided with at least one circling groove-like irregularity in communication with the annular clearance, and wherein the inner surface of the outer cylindrical body is provided with at least one circling grocve-lil e irregularity in communication with the annular clearance, each of said groovedike irregularities being discontinuous to provide groove ends of said irregularities, and the delivery conduits being in communication with the said groove-like irregularities of the inner and outer cylindrical bodies, respectively.

16. A structure as delined in claim 15, wherein the inlet conduit communicates with the annular clearance between the cylindrical bodies at a location adjacent to one end of each of the groovelike irregularities, and wherein the delivery conduits ccmmunicate with the respective groovelike irregidarities at locations adjacent to the other ends of said irregularities.

l?. A structure as defined in claim 14, wherein 18 l said foraminated sheet comprises a thin sheet of material provided with numerous slits extending through its thickness, said slits being discontinuous from each other.

18. A structure as defined in claim 14, wherein the inlet conduit communicates with the annular clearance adjacent to one end of said clearance, and wherein there are provided axially extending means in connection with the inner cylindrical body to subdivide the inner sub-pas sage into a plurality of successive circling partial sub-passages which are discontinuous from each other, and wherein there are provided separate delivery conduits in communication with the respective partial sub-passages of the inner subpassage for successive delivery of successive fractions oi lighter separated component.

19, A structure as dened in claim 14, wherein the inlet conduit communicates with the annular clearance adjacent to one end of said clearn ance, and wherein there are provided axially extending means in connection with the outer cy-1 lindrical body to subdivide the outer sub-passage into a plurality of successive circling partial subpassages which are discontinuous from each other, and wherein there are provided separate delivery conduits in communication with the respective partial sub-passages oi the outer subpassage for successive delivery of successive fractions of heavier separated component.

20. In a centrifuge a cylindrical rotor of substantially uniform diameter throughout its length, radially extending end walls at the ends of said rotor, means to journal said rotor for rotation on its cylindrical axis, means within the body of said rotor providing at least two concentric main passages within the body of the rotor circling said rotor and extending between said end walls, one of said main passages being of greater diameter than the other main passage and each main passage being co-axial with the axis of rotation and of substantially the same radius of rotation about said axis at all points around the circling length of said main passage, said means within the body of the rotor providing impervious inner and outer enclosing surfaces of said main passages, an inlet connection to the main passage of lesser diameter at one end thereof, outlet connections from said passage adjacent to the other end thereof, said outlet connections communicating with the said main passage at locations of radius, measured from the axis of cylinder rotation, different from ea-ch other, a radially extending conduit from said outlet connection of greater radius to one end of the main passage of greater diameter for delivery to said main passage of heavier coinponent separated within the main passage of smaller diameter, and outlet connections from said main passage of greater diameter adjacent to the other end of said passage of greater diameter, said last named outlet connections communicating with said main passage at locations of radius, measured from the axis of rotation, dirferent from each other, for delivery of separated components of diierent specific gravities from said last named main passage.

21. In a centrifuge a cylindrical rotor of substantially uniform diameter throughout its length, radially extending end walls at the ends of said rotor, means to journal said rotor for rotation on its cylindrical axis, means within the body of said rotor providing at least two concentric main passages within the body of the rotor circling said rotor and extending between 194 said end Walls, one of said main passages being of greater diameter than the other main passage and each main passage being co-axial with the axis of rotation and of substantially the same radius of rotation about said axis at all points around the circling length of said main passage, said means within the body of the rotor providing impervious inner and outer enclosing surfaces of said main passages, an inlet connection to the main passage of lesser diameter at one end thereof, outlet connections from said passage adjacent to the other end thereof, said outlet connections communicating with the said main passage at locations of radius, measured from the axis of rotation, different from each other, a radially extending conduit from said outlet connection 4of lesser radius to one end of the main passage of greater diameter for delivery to said main passage of lighter component sepa rated within the main passage of smaller diameter, and outlet connections from said main passage of Agreater diameter adjacent to the other end of said passage of greater diameter, said last named outlet connections communicating with said main passage at locations of radius, measured from the axis of rotation, different from each other, for delivery lof separated components of different specific gravities from said last named main passage.

References cited in the me of this patent UNITED STATES PATENTS Number Name Date 893,299 Bellany July 14, 1908 972,030 Smith Oct. 4, 1910 2,546,186 Hall Mar. 27, 1951 2,584,345 Hall Feb. 5, 1952 FOREIGN PATENTS Number Country Date 393,644 Great Britain June l2, 1933 

